Facile synthesis and long cycle life of SnSb as negative electrode material for Na-ion batteries

• This study is dedicated to an attractive new negative electrode for Na-ion batteries.
• This SnSb based electrode presents the longest cycle life ever reported for an electrode material vs. sodium.
• The capacity is maintained around 500 mAh/g over many cycles (0.1 mA) and may attain 650 mAh/g if the voltage window is extended.
• The capacity is at least twice the capacity of carbonaceaous electrodes (vs Na).
• The electrochemical mechanism is not trivially deduced from that of SnSb/li systems.

We report significant electrochemical performances promoting SnSb as one of the most promising negative electrode material for rechargeable batteries. Appropriately formulated with the carboxymethyl cellulose binder and cycled in fluoroethylene carbonate containing electrolyte, it could sustain a reversible capacity largely exceeding 525 mAh g− 1 over more than 125 cycles at a rate of C/2 (55 mA/g), with a satisfactory coulombic efficiency of more than 97%. To our knowledge, this is actually the longest cycle life ever reported for an electrode material vs. sodium.